DC power applications, such as aircraft power distribution systems, frequently include DC power sources at a voltage different from the voltage at which the power is to be distributed. One such example is the inclusion of a battery, or other stored energy component, in an aircraft. In order to allow the DC power source to provide power to the power distribution system at the proper voltage, a DC-DC power converter is utilized to adjust the voltage of the power provided.
By way of example, in an aircraft DC power distribution system, a battery, supercapacitor, or other similar power source connected to a distribution bus, is typically at a lower voltage than the voltage of the distribution bus. In order to increase the voltage of the battery to the level of the DC power distribution system, a boost converter is positioned between the battery and the distribution bus. Alternatively, if the voltage of the battery, or other power source is above the voltage level of the DC power distribution system, a buck converter is utilized to lower the DC voltage output from the battery. In other examples, the voltage of the power distribution system can vary, depending on the needs of the connected loads. In such an example, a buck/boost converter can be utilized to connect a DC power source, such as a battery or ultra-capacitor, to the DC power distribution system. In such an example, the battery or ultra-capacitor provides a power source/absorption for fast power transients, thereby allowing the generator to be sized to source the average load rather than the peak load.